The standard tables I've seen have been basic 'Wandering Monster' tables where you roll some dice in order to generate a random encounter.
I'm sure many have taken this concept further, but I haven't seen much advice around the net about how others construct random tables for their games. I'm looking for general ideas as well as examples.
In the wilderness I use a simple d6 or d8 and fill it with creatures depending on the surrounding areas. I'll usually have two or three extra entries and will add +2 or +3 at night. Thus, the first two or three entries are day-time only where as the last two or three creatures are night-time only.
The creatures encountered depend solely on the surrounding area. So a table can feature kobolds and dragons at the same time. The dragon might just fly overhead, obviously. When the party encounters the dragon, this means that it's lair must be somewhere in the surrounding area and they can start avoiding or searching the area.
You can turn an encounter table into a story by crossing elements off as they come up, and shifting the numbers appropriately (so that after 4 is rolled, it's crossed off, and the old five is now four). This dovetails nicely with the previous idea of changing die size, since the trick is that the most interesting encounters are on higher numbers, and as encounters get crossed off, it pushes the game towards them. In this way you can make an outdoor adventure have a similar cadence to a dungeon, getting tougher and more interesting as you press on.
If you find you're dealing with a very generic encounter table (just monster names, no details) try rolling an additional d8 and using this chart to set tone.
Deliberate: maybe they know something, maybe they just picked up a scent. Whatever the reason, they're hear because they're looking for the PCs.
Far From Home: This is not familiar territory for the creature. It wants to leave, but it's jumpy, and quick to violence.
Prepared: this is home base, and the monster know this terrain and has had time to prepare, choosing a good hiding place, laying traps or otherwise making ready. Monsters can't be surprised unless party is actively sneaking.
Distracted: something else has the creature's attention. May be avoidable.
Surprised: monster was clearly not expecting you. Players won't be surprised, monsters must roll.
Wary: monster is inclined to observe and follow the PCs and assess their strength before acting.
Civilized: monster is unexpectedly open to parlay, though communication maybe tricky.
Maddened: whether it's sickness, loss or just sheer cussedness, the creature is blind with rage.
While not incredibly deep, this sort of chart can help kickstart ideas for how to make the encounter something other than entirely generic.
I agree with Numenetics. Also, I've arranged the tables to take advantage of the bell-curve you get from rolling multiple dice (3d6 or the like). So the monsters at the middle of the table are more likely to occur than those at the ends.
I also have "countdown" tables. Say you have a portal to the Abyss slowly opening in your dungeon. Every day it remains open, I add one to all my rolls on the wandering monster table. The higher numbers have more demons in them, to the point where certain things that can't be rolled at first become possible and then very likely.
I've never been a fan of wandering monster table, but random encounters. The difference being that each of the encounters or situations is occuring when the players arrive at the scene. I'll try not to give too bad of an example.
Players come across two goblins fighting over a large fish. They have each other in headlocks and rolling around on the ground. Meanwhile the fish is flopping closer to the creek.
A goblin scouting party is marching down the trail. One of them is complaining loud enough to warn the players of their arrival. They have been marching for over two days and are starved. If they see they players they will collapse and plead for mercy. All they want it food.
The bushes move from the left of the party and as the players turn a large bear charges out attacking the closest character. Two bear cubs wait in a nearby tree. A player may try to lure the bears down with food. If the players are interested these black bear cubs can be trained.
The players come across a wounded woman (Clara). She claims to have been attacked by a goblin, but was able to kill it. She points towards the tall grass and a small goblin lies smoldering She will no say how she burned the goblin. She has a Wand of Fireballs hidden on her and doesn't want it taked away. She wants to return to town to her family. She has 10gp also hidden on her. She is the one who told the goblins which road the caravan was traveling in exchange for gold. One goblin thought he could make some easy money by attacking her.
The drawback of course is you can only use them once or twice. But I think if you develop ten or more that is all you need. The situation is set when the players come across it and their a small backstory of what is going on.
One good idea is to use different die types depending on the time of day, or the season, how close the party is to civilisation, and so on.
For example, if the nastier things come out at night, then you might stack those encounters at the top end of a 2d10 table, but during the day, you only roll 1d10+1d6. Close to town, you might only roll 1d10.
It's also worth cross-pollinating your encounter tables. While there may be no goblins in hex H6, for example, there is a goblin tribe in H7, so it's plausible that a small number might wander into the former hex. This helps to make the area seem alive and independent of the player-characters, and less like a series of discrete modules.
I'll also throw in my support for the very simple idea that "random encounter" doesn't necessarily mean "a monster attacks". Come up with a bunch of non-combat encounters to throw in there, whether they be traps, mysterious occurrences, a wandering merchant, and so on.
For the encounters which do turn out to be monsters, you can get a lot of use from a secondary "What Are the Monsters Doing?" type table, so even if you do roll 1d6 kobolds, they may in fact be chasing butterflies rather than getting ready for a fight.
Not sure if this is what you mean, but I think that making wilderness encounter tables level-independent increases their utility in creating interesting scenarios because it provides great opportunities to solve problems in ways other than direct combat, including running. I've had characters run from a nasty wilderness encounter and mark the area on the map, knowing that they wanted to come back and take care of that pesky X, creating some fun opportunities for fleshing out why the X was there in the first place, where exactly it lives, etc.
I've seen people write up random encounter charts with more than just monsters on 'em: weather-related challenges, terrain obstacles, interesting locations or just plain, you know, random stuff ("While tromping through the swamp, one randomly-selected character falls, face-first, into the mud, no save. Character is all mucky and stuff, smells bad and gets a malus on reaction rolls until he/she can get cleaned up.").
As for distribution, well, how about:
(D6)
1-3: Monster
(subtable)
4-5: Terrain Obstacle
(Subtable)
6: Weirdness
(Subtable)
...or whatever balance you want. Maybe Weirdness gets the 1-3 slot, and monsters are only 1/6.
Tables with a bell curve can be fun if you want some monsters to be rarer than others. Just use more than one dice. 3d6 for example and have entries for 3 to 18.
Also using a D100 with ranges for different monsters can be a nice way of controlling the weighting of the randomness to a finer degree.
A short example:
1: Red Dragon
2-10: Bulette
11-30: Orc
31-60: Goblin
61-70: Wolf
71-80: Owlbear
81-85: The Dragon of Tyr
86-90: Giant Boar
91-95: White Dragon
96-98: Purple worm
99: Sadie the Guard Mouse
00: Mr. Hat
You can assign ranges of different sizes, and different probabilities, to the monsters you want to appear more or less often.
Check out Abulafia, which is a sort of wiki random-stuff generator. It's had some server issues, but when it's up, it's awesome. You edit wiki pages to create lists of stuff. It can be nested and complicated, so you can use it to auto-generate words in a language using some simple rules and syllable lists, for example. You could easily do "nested" random encounter lists with different probabilities using this tool.
I often use two dissimilar dice, such as d6+d10, in order to get the flat spot.
I pick a general threat level for an area, and put slightly higher level encounters at the ends, and slightly lower in the flat-spot.
For example, a relatively safe woods might be "level 3" and fairly uniform: d4+d6
2 (1/24): young wyvern
3 (2/24): Carrion Crawler
4 (3/24): Elven Hunters
5 (4/24): Herd Animal (3hd)
6 (4/24): Herd Animal (2hd)
7 (4/24): wolves
8 (3/24): 3hd hunting cat
9 (2/24): other hominids
10 (1/24): Sprites
This works for lists in electronic format that you can easily edit, e.g. text files.
Have a list of encounter and events and whatnot, as usual. Whenever you should roll on it, roll for example a d6. That's the encounter. Next consider: Was the encounter a one-off thing? If yes, remove it from the list. If no, change its place to be the last one on the list.
When you get an idea for a new encounter you want to happen soon, add it to the beginning of the list. If you want it to maybe happen sometimes but there's no hurry, add it to the end.
As a bonus, you can roll pretty much any die and this works well. If your table has 13 entries and your roll of d20 is 16, simply treat it as 16-13 = 3 (so roll d20 and use the equivalence class modulo 13), though I'd rather use a smaller die to speed the table look-up. If you roll several dice and the table is long, the first few results won't be available, and though this could be handled, I'd rather simply roll a single die.
Clearing an area
To simulate clearing an area, add a bunch of "empty" or non-creature entries to the table. They'll get more common if you move them to the end of the table when they come up but remove other entries (perhaps unique monsters) when they are rolled and if they are defeated.
Random encounter tables are a way to fill your game with encounters. In reality by themselves they just tell the referee that in the immediate vicinity of the party there is a kind of creature os "local special", but tell nothing much more about the encounters (what the creature is doing, how it will react, what kind of interaction will be).
The typical table is filled with local fauna (wolves, snakes, bloodbriar, cultists) and local specials (hymns sung by cultists in their hidden temple brought by the wind, volcano erupts): just cram in what you expect to be encountered while moving about there. I recommend a healty mix of the two kinds.
The method given in the D&D 4e DMG isn't bad: use a card deck.
I use index cards:
So you make one card for each, just go through the deck.
Next, shuffle them up, and then run through it again to assign a level that ranges on each card from party level -2 to party level +5. with the majority of the numbers being equal to party level.
Shuffle them up again, turn to the back of the monster book of your choice (or monster builder or what-have-you) and pick out monsters that fit each card. For example "Brute level 4"- you just look what brutes fit. Mark it down.
You could be totally random about this or more structuyred- for example, doing an orc or fey themed deck. See examples below.
Finally, building encounters: figure out the encounter budget and draw the first few cards to fill up that encounter. Skirmishers count as two monsters, solo's count as 1, minions count as 4. A lurker gets added in after you do the entire encounter. Keep drawing until it fills the XP budget up.
Final step: try to figure out how this makes an encounter. if it makes sense, you have an encounter. If it doesn't? Just draw more cards.
Examples:
Good: You draw a gnome arcanist, a pseudo dragon, and a group of wisp-wraiths (minions): great encounter. The gnome and the dragon are friends, adventuring together. The wisp wraiths are firefly spirits in a jar the gnome is carrying around. He just smashes the jar in round 1.
Needs work: You draw an orc raider, an orc brute, a halfling slinger, and several spiders. hmm. You could drop the spiders, and redraw. Maybe the halfling is a particularly charismatic bad guy, and the orcs are his gang.
As you start to increase the encounter area, adding new monster cards can be used to create a more themed area. For example- you could create a less random deck that is used just for underdark areas or a sylvan woods.
The Savage Worlds edition of The Day After Ragnarok has some very nice encounter tables for The Poisoned Lands that you could adapt to many different settings. After determining that there's an encounter at all, you roll for an encounter type (People, Animal, Event, etc.,) and then each type has another table to roll on and sometime sub-tables. There's an Allegiance table for People, for example. And on top of that, there's an entire Adventure Generator in the book too. Like most Ken Hite products, DaR is full of interesting ideas.
I created wilderness encounter cards that include poison ivy, losing items, hostile creatures , etc.
